JPH0322725Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the improvement of optical fiber connectors.
In particular, it relates to an optical fiber connector suitable for connecting multi-core optical fiber cables.

Conventionally, as an optical fiber connector used for connecting multi-core optical fiber cables, for example, the one shown in FIG. 1 has been known. In Figure 1, the multi-core optical fiber cable 1 to be connected
One end of each of optical fibers 2a and 1b is stripped to form optical fibers 2a and 1b.
2b... are exposed, and each optical fiber 2a, 2b...
are optical fiber fixing plugs 3a and 3b of approximately equal length.
..., and its end surface is aligned with the tip surface of the optical fiber fixing plugs 3a, 3b.

These optical fiber fixing plugs 3a, 3b...
are inserted and fixed into fixed plug holding members 4a and 4b, each having a lotus root-shaped guide hole at a corresponding position.

The fixing plug holding members 4a, 4b have different lengths, and are formed so that when they are abutted, both end surfaces of the optical fiber fixing plugs 3a, 3b are abutted.

Further, special cylindrical holding fittings 5a, 5b are fitted around the outer peripheries of both fixing plug holding members 4a, 4b, and the bases of these holding fittings 5a, 5b are provided with protective fittings for the multi-core optical fiber cables 1a, 1b. Cable clamps 6a and 6b spanning the sheath are screwed together.

Further, a protruding line 7 is formed in the circumferential direction on one end of the outer periphery of the holding fittings 5a, 5b, and a connecting cylinder 9 is fitted into this protruding line 7 by engaging a groove 8 formed on the inner circumference. There is.

Moreover, screws that can be screwed together are carved on the inner periphery of the tip of the connecting cylinder 9 and the outer periphery of the tip of the holding fitting 5a.

In the conventional optical fiber connector configured as described above, the optical fiber fixing plugs 3a and 3b are inserted into the guide holes of the fixing plug holding members 4a and 4b, the holding fittings 5a and 5b are butted, and the connecting ring 9 is attached to the holding fitting 5a. The connection is made by screwing it onto the outer periphery of the.

By the way, in such optical fiber connectors, in order to send the light sent from one optical fiber to the other optical fiber with as little loss as possible, it is necessary to connect the optical fibers so that the end faces of the optical fibers are accurately butted together. There is.

Therefore, in the conventional optical fiber connector described above, in order to accurately butt the end surfaces of the optical fibers, it is necessary to hold the fixed plug holding member 4 in the connected state.
It is necessary to align the central axes of the guide holes of the fixed plug holding members 4a and 4b completely, but in order to do this, it is necessary to align not only the guide holes of the fixed plug holding members 4a and 4b, but also
The machining accuracy of the outer diameter, the inner diameter of the holding fittings 5a, 5b, etc. must also be made high, which is extremely difficult. Particularly in the case of multi-core optical fiber cables, the relative positions of the guide holes must also be matched to ensure smooth attachment and detachment, making the processing even more difficult.

In addition, in the above-mentioned type of optical fiber connector, the optical fiber fixing plug 3b has its tip inserted and fixed into the approximately middle part of the through hole of the fixing plug holding member 4b, so that it is fixed when the optical fiber connector is attached or detached, for example. Fine dust, etc. enters from the tip of the plug holding member 4b, and this enters the optical fiber 2.
If it adheres to the end surface of b, it cannot be easily removed, which has the disadvantage of increasing optical loss at the connection.

The present invention has been made to eliminate such conventional drawbacks, and a recess is formed in each front surface of a pair of holding fittings, so that each end face of the optical fiber fixing plug can come into contact with the holding fittings when the holding fittings are opposed to each other. Holes 23a and 23b for fitting and fixing the optical fiber fixing plug are provided in the holding fitting so that the optical fiber fixing plug is fixed in these holes and the optical fiber fixing plug is brought into contact with the holes 23a and 23b. A guide sleeve having a through hole 32 through which both fixing plugs are inserted is fitted across each of the recesses of both of the holding fittings, and both of the holding fittings are removably engaged with a connecting fitting. In the fiber connector, the through hole of the guide sleeve has a guide hole that is precisely finished to match the outer diameter of the optical fiber fixing plug, and the outer diameter is slightly smaller than the inner diameter of the through hole of the guide sleeve. A cylindrical sleeve with a small diameter and a guide surface made of a tapered or curved surface is loosely inserted into the entrance of the guide hole, and a locking mechanism is provided at the entrance of the guide sleeve to prevent the cylindrical sleeve from slipping out. It is an object of the present invention to provide an optical fiber connector characterized in that a stopper member is disposed.

The details of the present invention will be described below with reference to an embodiment shown in FIGS. 2 and 3.

In the figure, optical fiber cable 1 to be connected
The ends of 1a and 11b are stripped in steps as in the conventional case,
Each optical fiber 12a, 12b is inserted and fixed into an optical fiber fixing plug 13a, 13b. On the outer periphery of the optical fiber fixing plugs 13a, 13b, two grooves 14a, 14a', 14b, 14' are formed in the circumferential direction.
are formed, and reinforcing materials 15a, 15b for the optical fiber cable are formed in the grooves 14a', 14b' near the rear end.
is fixed. These fiber optic fixing plugs 1
3a, 13b engage the floating O-rings 17a, 17b in the grooves 14a, 14b near the tips of the fixed plug holding members 16a, 16b, which have guide holes drilled in a lotus root shape.
They are inserted and fixed so that their respective tips protrude from the holding members 16a and 16b.

On the front surfaces of the holding members 16a, 16b, packing holding members 18a, 18b are arranged, which have through holes for inserting the optical fiber fixing plugs 13a, 13b at the same positions as the holding members 16a, 16b.

Annular recesses 19a, 19b are formed inside the through holes of the packing holding members 18a, 18b,
Waterproof packing 2 is provided in the recesses 19a and 19b.
0a and 20b are fitted.

The holding fittings 21a and 21b are arranged at 1 along the longitudinal direction.
It has a cylindrical shape with a guide groove 22 in the form of a strip, and the inside thereof has large diameter parts 22a, 22b and a small diameter part, that is, a hole 2 for fitting and fixing the optical fiber fixing plug.
3a, 23b and screw portions 24a, 24b, the large diameter portions 22a, 2 of the small diameter portions 23a, 23b
Annular protrusions 25a, 25b are formed at positions close to 2b, and annular recesses 26a, 26 are formed near the annular protrusions 25a, 25b.
b is formed, and waterproof packings 27a and 27b are fitted.

The holding members 16a, 16b to which the optical fiber fixing plugs 13a, 13b are attached are attached to the holding fittings 21a,
The stepped portions 28a, 28b provided at the tips of the packing holding members 18a, 18b from the threaded portions 24a, 24b, respectively, into the inside of the packing holding members 18a, 21b are connected to the annular protrusions 25a, 25b.
The fixing rings 29a and 29b, which have threaded grooves on their outer peripheries, are inserted until they are locked in the threaded parts 24a and 29b.
24b and the whole is fixed.

The guide sleeve 30 has holding fittings 21a and 21b.
The guide sleeve 30 has a cylindrical shape with a guide 31 along the longitudinal direction that fits into the cylindrical space formed by the inner guide grooves 22a, 22b and the small diameter portions 23a, 23b when they are butted together.
Through holes 32 are concentrically formed at positions corresponding to the optical fiber fixing plugs 13a and 13b, respectively.

A cylindrical sleeve 33 having an outer diameter slightly smaller than the inner diameter of the through hole is loosely inserted into each through hole 32.

The guide holes of the cylindrical sleeves 33 are precisely finished to match the outer diameters of the optical fiber fixing plugs 13a and 13b, and near both ends there are guide holes made of tapered or curved surfaces. Surfaces 34, 34 are formed (the figure shows the case of a curved surface).A step hole is formed at both ends of the through hole of the guide sleeve 30, and a step hole is formed in the step hole to prevent the cylindrical sleeve 32 from slipping out. Ring-shaped retaining fittings 35, 35 are fixed in contact with each other. In addition, this retaining metal fitting 3
The inner diameters of the holes in the rings 5 and 35 are larger than the maximum outer diameter of the guide surface 33, and guide surfaces 36 and 36 are formed that slope toward the outside. In the illustrated embodiment, a flange 38 having a packing holding groove 37 on the surface facing the cable clamp 6a is provided at the rear end of one of the holding fittings 21a, and a waterproof packing 39 is fitted into the holding groove 37. A packing 39 is pressed and fixed to a side plate 40 of a device (not shown). In addition, the above-mentioned holding fitting 21a
A concave groove 41 is spirally formed on the outer periphery of the connecting ring 4, and a protrusion 42 that engages with the concave groove 41 is provided on the inside of the outer periphery of the other holding fitting 21ab.
3 is engaged.

In the optical fiber connector of the present invention configured as described above, the guide hole of the cylindrical sleeve 33 is processed by precision finishing so as to match the outer diameter of the optical fiber fixing plugs 13a and 13b, and the through hole of the guide sleeve 30 is 32, so the guide sleeve 30 and holding fittings 21a, 21
Even if the machining accuracy of b is somewhat low, the optical fiber fixing plugs 13a, 13b can be placed exactly on a straight line, and therefore the optical fiber fixing plugs 13a, 13b
The end faces of the two are precisely butted together. Note that in order to prevent the end faces of the optical fibers 12a and 12b from being damaged,
The end faces of the optical fibers 12a, 12b may be set back very slightly from the end faces of the optical fiber fixing plugs 13a, 13b.

Further, the guide sleeve 30 includes the holding fittings 21a,
Since the optical fibers 12a and 12b can be removed from each other, even if dust or the like adheres to the end surfaces of the optical fibers 12a and 12b, it can be easily removed. Furthermore, as shown in the embodiment, the optical fiber fixing plugs 13a, 13b are attached to the floating O-ring 1.
7a and 17b, the fixed plug holding member 16
If the optical fibers 12a and 16b are engaged, movement in the thrust direction is allowed, so even if the end surfaces of the optical fibers 12a and 12b come into contact, strong pressure will not be applied and damage will be reduced.

Furthermore, when the abutting portions of the optical fibers 12a, 12b are sealed with waterproof packings 20a, 20b, etc., water vapor and the like are prevented from entering the abutting portions, and light loss due to this is also prevented.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a conventional optical fiber connector, FIG. 2 is a vertical sectional view showing an embodiment of the optical fiber connector of the present invention, and FIG.
FIG. 11a, 11b...optical fiber cable, 12
a, 12b...optical fiber, 13a, 13b...
Optical fiber fixing plug, 14a, 14a', 14
b, 14b'... Concave groove, 15a, 15b... Reinforcement material, 16a, 16b... Fixed plug holding member, 1
7a, 17b...Floating O-ring, 18
a, 18b...packing holding member, 20a, 2
0b... Waterproof packing, 21a, 21b... Holding metal fittings, 30... Guide sleeve, 33... Cylindrical sleeve, 34... Guide surface.

Claims (1)

[Scope of utility model registration request] A recess is formed in each front surface of the pair of holding fittings, and the optical fiber fixing plug is inserted and fixed in such a manner that each end face of the optical fiber fixing plug can come into contact when the holding fittings are opposed to each other. Hole 23a,
23b is provided in the holding fitting, and the optical fiber fixing plug is fixed in this hole, and the guide sleeve has a through hole 32 through which both fixing plugs are inserted when the optical fiber fixing plug is brought into contact with the guide sleeve. In an optical fiber connector that is fitted across the respective recesses of both holding fittings, and in which both holding fittings are removably engaged with a connecting fitting, the outer side of the optical fiber fixing plug is inserted into the through hole of the guide sleeve. The guide hole has a precision finish to match the diameter, the outer diameter is slightly smaller than the inner diameter of the through hole of the guide sleeve, and a guide surface consisting of a tapered surface or a curved surface is provided at the entrance of the guide hole. An optical fiber connector characterized in that the formed cylindrical sleeve is loosely inserted therein, and a locking member for preventing the cylindrical sleeve from coming off is disposed at the entrance of the through hole of the guide sleeve.